Diabetes mellitus has a main feature of a symptom such as polydipsia, polyuria, or weight loss, or a chronic high blood glucose level, which is a disease generally accompanied by complications such as retinopathy, nephropathy, and peripheral nerve disorders. Diabetes mellitus is classified by its causations into primary diabetes mellitus (insulin-dependent diabetes mellitus (type I diabetes mellitus) and non-insulin-dependent diabetes mellitus (type II diabetes mellitus)), secondary diabetes mellitus (pancreatic diabetes mellitus, pancreatic exocrine/endocrine diabetes mellitus, and drug-induced diabetes mellitus), and the like. Further, diabetes mellitus has been known to be a risk factor for an arteriosclerotic disease such as a cardiac infarction or a cerebral infarction.
Conventionally, as a method of treatment of diabetes mellitus, improvement in lifestyle by, for example, a dietetic treatment, a kinesitherapy or the like, and a method of treatment by an insulin injection, a drug administration or the like have been performed. In addition, a substance derived from a plant has been used in the treatment of diabetes mellitus (see, for example, Patent Publication 1).
On the other hand, as a method of treatment of diabetic nephropathy, conventionally, a method of treatment with sulodexide derived from mammalian intestinal mucosa (see Patent Publication 2), efonidipine hydrochloride (see Patent Publication 3), Salviae Miltiorrhizae Radix herb (Patent Publication 4), or the like has been performed.    Patent Publication 1: Japanese Patent Laid-Open No. 2002-068995    Patent Publication 2: Japanese Patent Laid-Open No. Hei 6-329541    Patent Publication 3: Japanese Patent Laid-Open No. Hei 11-246417    Patent Publication 4: Japanese Unexamined Patent Publication No. 2003-510286